1. Field of the Invention
The present invention relates to an active avermectin analogue, 26-epi-avermectin B.sub.1 a, which is active as an antiparasitic for use in treating animals and pets for parasitic infections.
2. Brief Disclosures in the Art
Avermectins are a well known class of antiparasitic agents which are effective in treating a variety of animals and pets to combat a variety of parasitic infections.
The term avermectin (previously referred to as C-076) is used to describe a series of compounds isolated from the fermentation broth of an avermectin producing strain of Streptomyces avermitilis and derivatives thereof. The morphological characteristics of the culture are completely described in U.S. Pat. No. 4,310,519 and 4,429,042 and are incorporated herein by reference. They describe the general class of avermectins and their broad spectrum activity against insect pests, acarid, free-living nematodes and parasites affecting animals. They particularly exhibit efficacy against the important parasitic worms or arthropods afflicting livestock, domesticated animals or humans.
The avermectin compounds are a series of macrolides, each of which is substituted thereon at the 13-position with a 4'-(.alpha.-L-oleandrosyl)-.alpha.-L-oleandrose group. Avermectin compounds and the specific derivative thereof of this invention, have a very high degree of anthelmintic and antiparasitic activity.